Fuel Cell System and Adaptive Open-Loop and Closed-Loop Control Method and Apparatus Therefor

ABSTRACT

Closed-loop and open-loop systems are used for automated control of the operation of arbitrary systems. An open-loop control apparatus, which controls at least one controlled variable of a system such as a fuel cell system, has a pilot control module and an associated storage module, for storing pilot control characteristic data. The pilot control module carries out pilot control, based on a pilot control value determined from a desired value of the controlled variable from the pilot control characteristic data. A closed-loop control module performs closed-loop control of the controlled variable using a controlled portion determined on the basis of the actual value of the controlled variable. In the open-loop control apparatus, the pilot control value and the controlled portion each make respective contributions to a manipulated variable. An adaptation module matches the pilot control characteristic data in the storage module adaptively during the run time of the open-loop control apparatus.

This application is a national stage of International Application No.PCT/EP2006/009140, filed Sep. 20, 2006, the entire disclosure of whichis herein expressly incorporated by reference.

The present invention relates to an open-loop and closed-loop controlapparatus for controlling at least one controlled variable of a fuelcell system, and to a method for controlling at least one controlledvariable of a fuel cell system.

Closed and open-loop systems are used for automated control of theoperation of many types of systems. Such controls are particularlyimportant in the field of vehicle technology.

German patent document DE 101 600 51 A1 discloses for example, a methodand apparatus for monitoring a motor vehicle subsystem by determining anactual operating variable of a subsystem of the vehicle to assess itsfunctionality, and outputting a control signal according to therequirement of the assessment result. An operating state of the motorvehicle is adjusted according to the requirement of the control signal.The actual operating variable of the subsystem is determined viapredetermined characteristics, which for example output a correspondingactual engine torque dependent on a sensed wheel force component. Thecharacteristics can optionally be matched adaptively; they are generatedor changed during the course of the operating time of the entire system,so that connections between the sensed wheel force component and theeffective actual engine torque can always be taken exactly therefrom.

German patent document DE 4228053 A1 relates to a method for thecylinder-specific characteristic control and adaptation for theelectronic control of internal combustion engines with multiplecylinders. This method, which uses only an open-loop control, providesthat a used characteristics field is continually adaptively optimized atthe points of the parameter space given by the operating parameters ofthe respective individual cylinders, with regard to at least one targetvariable.

From closed-loop control technology, it is known that, in regulatedsystems (particularly non-linear systems), a control device is usedwhich simultaneously uses both open loop control of the manipulatedvariables by means of a characteristic curve or characteristic field,and regulation (closed-loop control) of the manipulated variables bymeans of an additive regulating portion. Open-loop control (pilotcontrol) has the advantage that it permits direct access to themanipulated variables (and thereby the controlled variables), so thatvery high dynamics can be achieved. On the other hand, the use of PID orcondition controllers to generate the additive controlled portion makeit possible to readjust slow dynamic or stationary system conditions.Such open-loop control devices form the closest state of the art.

One object of the invention is to provide an open-loop control apparatuswhich is improved relative to the closed-loop quality.

Another object of the invention is to provide a corresponding system inthe form of a fuel cell system, a corresponding method, and acorresponding computer program.

These and other objects and advantages are achieved by the open-loop andclosed-loop control apparatus according to the invention, which issuitable or configured to control at least one controlled variable of asystem. The system in this case may be a non-linear system (or a fuelcell system). At least one controlled variable of the system iscontrolled; however, two or more controlled variables of the system canalso be controlled, either independently of one another, or partially inmutual dependence upon one another.

The open-loop and closed-loop control apparatus is preferably formed asan electronic processing device, for example as a control device,personal computer, microcontroller, DSP embedded system or the like.

The open-loop control apparatus comprises a pilot control module and anassociated storage module for storing pilot control characteristic data.The pilot control module permits direct access to the controlledvariable of the system, so that the pilot control reacts without (ornearly without) delay upon a fast operating point change of the system.The pilot control module is configured so that a pilot control value isdetermined on the basis of a desired value of the controlled variable,from the stored pilot control characteristic data.

The open-loop control apparatus further comprises a closed-loop module(for example, a PID or condition controller), with the open-loop modulebeing formed for controlling the controlled variable. The open-loopmodule updates a deviation of the controlled variable from the guidevariable (desired value presetting) via a sensor system.

The open-loop control apparatus is formed using program technologyand/or circuitry, configured such that the pilot control value and thecontrolled portion provide respective contributions to a control value,which is (or can be) used to control the at least one controlledvariable of the system. The pilot control module and the closed-loopmodule can thus be arranged in parallel to one another, in particular insuch a manner the pilot control value and the controlled portion areadded to form the control value. Alternatively, the pilot control valueand the control value of the manipulated variable may be supplied at theinput of the closed-loop module, so that the pilot control valueprovides a contribution to the control value in this manner.

According to the invention, an adaptation model is provided in theopen-loop control apparatus, which is formed to match the pilot controlcharacteristic data in the storage module adaptively during the run timeof the open-loop control apparatus or the system.

The inventors have determined that the combination of closed-loop modeand pilot control is principally capable of controlling systems, evenwith pilot control characteristic data which are defective or obsoletedue to wear or varying system tolerances. However, the control dynamicsof the system are adversely affected due to the adjustment of thesefaults by the closed loop. An exact pilot control is enabled by the useof adaptive pilot control characteristic data, such that the controlledportion is near zero in the ideal case, ensuring robust system behaviorin any case, with quickly adjustable system conditions. The controlledportion, and therewith the controlled deviation, are thereby at leastlimited to a small region with the open-loop control apparatus accordingto the invention.

In a preferred embodiment, the pilot control characteristic data maycomprise a one-dimensional characteristic, a two- or multi-dimensionalcharacteristic field, a corresponding raster characteristic orcharacteristic field. In a practical realization, for example, the pilotcontrol characteristic data are stored in the storage module as alook-up table (LUT). Moreover, the pilot control characteristic data maybe composed of a basic characteristic/characteristic field and a deltacharacteristic/characteristic field, with only the deltacharacteristic/characteristic field being changed by the adaptation. Thestorage and change of the pilot control characteristic data aretechnically solved, for example by describing the characteristicfield/characteristic contents in the RAM/ROM storage region of thestorage module. The storage contents are thus preferably still presentin the storage module (preferably in a persistant manner), afterswitching the open-loop control apparatus off and on again.

In a particularly preferred embodiment of the invention, the adaptationmodule is formed for the adaptation of the pilot control characteristicdata on the basis of stationary or virtually stationary controlledportions. The present invention thus provides pilot controlcharacteristic data (in particular characteristic field or deltacharacteristic field) that are adjustable for the run time, by changingthe preset characteristic field contents in the respective operatingpoint by the in particular stationary controlled portion.

The adaptation process is preferably carried out on the basis ofcontrolled portions, which are taken from the closed loop module and/orthe system in a stationary and/or virtually stationary condition. In apreferred embodiment, it is checked by means of a routine if the systemis in a stationary condition, and the controlled portion, which adjustsby means of the closed-loop module, is determined and consulted foradaptation.

The adaptation model is preferably configured such that the adaptationof the pilot control characteristic data is converted by a surfaceinterpolation method, or, in the case of a characteristic, by a linearinterpolation method. In this case, preferably the stationary controlledportion is converted to present support points of the pilot controlcharacteristic data, and the resulting portion is added to the updatedsupport value in the case of a characteristic field/characteristic.Alternatively, it is inserted directly as a delta value to the basiccharacteristic field in the case of a delta characteristic field.

In a preferred further embodiment of the closed-loop control apparatus,the adaptation module is formed in such a manner that the adaptationdegree of the pilot control characteristic data (in particular, theadaptation per adaptation iteration) is smaller than 1 (100%),preferably in the region of 1% to 50%, so as to avoid feedbacks of thecontroller with the pilot control module during the adaptation process.This measure at least substantially decouples the adaptation processfrom the closed-loop apparatus, by keeping the measure of the adaptationsmall.

Alternatively and/or additionally, the pilot control characteristic dataare adapted only for these support points which are not currently in theregion of the operating point of the system (that is, are for exampletime-delayed). The pilot control characteristic data are for exampleonly updated after leaving the respective operating points.

With a preferred practical realization of the open-loop controlapparatus for a fuel cell system, the controlled variable is formed insuch a manner that it acts on one or more of the following systems: anair compressor, an exhaust gas throttle flap, a humidifier bypassthrottle flap, control valves and/or a recirculation pump of the fuelcell system. The open-loop control apparatus is particularly suitablefor triggering components, whose system properties depend heavily onchanging environmental conditions or wear and/or aging.

A further object of the invention relates to a method of con oiling atleast one controlled variable of a system (particularly a fuel cellsystem), using an open-loop and closed-loop control apparatus.

With the method of the invention, a pilot control value is determinedfrom stored pilot control characteristic data based on a desired valueof the controlled variable, and a controlled portion may possibly bedetermined in addition to the pilot control value, based on the desiredvalue. A control value is formed on the basis of the pilot control valueand the controlled portion.

In the method according to the invention, the pilot controlcharacteristic data are matched adaptively during the run time of thesystem. The present invention thereby provides a characteristic field ordelta characteristic field which can be adjusted to the run time, withthe preset characteristic field contents being changed in the respectiveoperating point in particular by a stationary controlled portion.

In a preferred embodiment of the method, it is first checked via aroutine if the system is in a stationary condition. The controlledportion which is adjusted by the controller is then determined, which isconsulted for the adaptation of the pilot control characteristic data ina further step.

A further object of the invention relates to a computer program withprogram code means for executing the method according to the invention,when the computer program is executed on a computer or an open-loopcontrol apparatus.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The single FIGURE is a block diagram of an open-loop control apparatusaccording to an embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an open-loop control apparatus 1 in the form of a blockdiagram as a first embodiment of the invention. The open-loop controlapparatus 1 has a first input 2, for the reception of a desired valuey_(d). A second input 3 serves for the reception of an actual valuey_(m). The open-loop control apparatus 1 comprises a control valueoutput 4, at which the determined control value u is provided. Theopen-loop control apparatus 1 thus corresponds to a classical open-loopor closed-loop device with regard to inputs and outputs, in which ameasured actual value y_(m) (or which is obtained in another manner)follows a desired value y_(d) by generating and outputting a controlvalue u.

The closed-loop or open-loop system 5 is for example formed as one ormore components of a fuel cell system (not shown). The closed-loopsystem 5 comprises a controlled variable y which is acted on by thecontrol value u via an actuator (not shown), and possibly bymalfunctions v. The actual value of the controlled variable y ismeasured by a sensor 6, which generates the actual value y_(m) on thebasis of the measurement, and applies it to the second input 3. Only onecontrolled variable y and a sensor 6 were chosen for the simplifieddepiction of the example of the embodiment. However, several controlvariables y dependent on one another (or also independent), can beregulated or controlled simultaneously with more complex embodiments.Also, the actual value of the controlled variable y can be determined byother methods, such as relative measurement, derivation, estimation orthe like.

The open-loop control apparatus 1 comprises two parallel signal pathsstarting from the inputs 2 and 3. A first signal path comprises aclosed-loop device, and the second path comprises a pilot control.

The actual value y_(m) and the desired value y_(d) of the controlledvariable y are combined in the first signal path in a differentialmember 7, and the closed-loop difference is passed to a controller 8,which determines a controlled portion u_(adder). The latter is finallypassed to an adder 9, which merges the controlled portion with othervalues, as will be explained in the following.

The second signal path, relating to the pilot control, is divided intotwo sub-paths which deliver a pilot control value u_(base) or du_(base)to the adder 9.

The sub-path positioned further upwards in FIG. 1 guides the desiredvalue y_(d) from the first input 2 to a look up table (LUT) module 10,in which a basic characteristic field is stored. The pilot control valueu_(base) is determined by the desired value y_(d) from the basiccharacteristic field in the LUT model 10, and—as alreadyexplained—passed to the adder 9.

The lower sub-path in FIG. 1 guides the desired value y_(d) to a dLUTmodule 11, which has a delta characteristic field. In the dLUT module11, a delta pilot control value du_(base) is assigned to the desiredvalue y_(d), which is again passed to the adder 9.

While the basic characteristic field in the LUT module remains unchangedover time in the present example of an embodiment in FIG. 1, the deltacharacteristic field in the dLUT module 11 is adapted in response ontemporal changes of the closed-loop system 5 (for example wear, aging,contamination etc.). The division of a pilot control module into LUTmodule 10 and dLUT module 11 is not compulsory. Rather, the basiccharacteristic field and the delta characteristic field can just thesame be merged to a common characteristic field, which is matched to theclosed-loop system 5 adaptively during the run time. It is also possiblethat the characteristic field is formed only one-dimensional, that is,as a characteristic, or comprises two, three or more dimensions.

For the adaptation of the delta characteristics field in the dLUT module11, the currently measured actual value y_(m) and the current controlledportion u_(adder) are added to the desired value y_(d). As explained inmore detail hereinafter, the delta characteristic field in therespective operating point y_(m) is changed by the controlled portionu_(adder). The adaptation is based on the proposition that thecontrolled portion should strive to zero in an optimally adjusted deltacharacteristic field. The magnitude of the controlled portion is therebya measure of the quality (in particular, the up-to-dateness) of thedelta characteristic field. The delta characteristic field is correctedwith the controlled portion u_(adder) in the operating point y_(m) or inthe corresponding support point for the adaptive adaptation of the deltacharacteristic field. It is ensured during the transfer, that thecontrolled portion u_(adder) is formed in an engaged manner, that is,stationary or virtually stationary. So as to avoid a feedback betweenthe control module 8 and the pilot control module 10 or 11, theadaptation degree (a measure of the adaptation of the pilot controlvalue in the characteristic field) is chosen to be significantly smallerthan 1 (100%) and/or a temporal decoupling of the adaptation of thecharacteristic field value is provided in the respective operatingpoint.

A mathematical derivation of the adaptation process is introduced in thefollowing for the best explanation of the adaptation process, whichrepresents a possible execution or depiction of the adaptation process:

The open-loop control apparatus 1 comprises the pilot control modulewhich is formed of the LUT model 10 and the dLUT model 11, and whichconverts a linearized transfer function. In a particularly practicalembodiment, the transfer function is represented by a pilot controlfunction u_(base)=LUT(y_(d)). The open-loop control apparatus 1 can beseen as a look-up table (LUT)-based controller for non-linear processesin this case.

A look-up table (LUT) is a condition field from the mathematical pointof view, which can be described as follows:{u_(base)(i)=LUT(y_(d)(i)),i= 1,N}, wherein the control valuesy_(d)(i)⊂R^(1U2) are copied to the control values u_(base)(i)⊂R, whereinthe condition field has for example been determined by offlinemeasurements.

As the depicted look-up table is shown as a raster field or rastercharacteristic, values between the raster points or support points aredetermined by an interpolation method.

As mostly only look-up tables for one-dimensional or two-dimensionalfields are needed for practical use, only these are depicted in thefollowing. Look-up tables having higher dimensions can nevertheless alsobe used in principle.

For a one-dimensional look-up table

{u _(base)(i)=LUT(y _(d)(i)),i= 1,N }

e.g., in the form:

y_(d) y_(d)(1) . . . y_(d)(k) y_(d)(k + 1) . . . y_(d)(N) u_(base)u_(base)(1) . . . u_(base)(k) u_(base)(k + 1) . . . u_(base)(N)the pilot control value u_(base) at the time t is calculated as follows:

u _(base)(t)=l _(k) u _(base)(k)+l _(k+1) u _(base)(k+1)

wherein the weighting factors are calculated as follows:

${{0 < l_{k}} = {\frac{{y_{d}\left( {k + 1} \right)} - {y_{d}(t)}}{{y_{d}\left( {k + 1} \right)} - {y_{d}(k)}} \leq 1}},{{0 < l_{k + 1}} = {\frac{{y_{d}(t)} - {y_{d}(k)}}{{y_{d}\left( {k + 1} \right)} - {y_{d}(k)}} < 1.}}$

For two-dimensional look-up tables, which are displayed as follows:

{u_(base)(i, j) = LUT(y_(td)(i), y_(2d)(j)), i = 1,N, j = 1M}, e.g.,u_(base)(i, j) y_(1d)(1) . . . y_(1d)(k) y_(1d)(k + 1) . . . y_(1d)(M)y_(2d)(1) u_(base)(1, 1) u_(base)(1, . . . ) u_(base)(1, k) u_(base)(1,k + 1) u_(base)(1, . . . ) u_(base)(1, M) ⋮ u_(base)(⋮, 1)u_(base)(⋮, . . . ) u_(base)(⋮, k) u_(base)(⋮, k + 1)u_(base)(⋮, . . . ) u_(base)(⋮, M) y_(2d)(l) u_(base)(l, 1)u_(base)(l, . . . ) u_(base)(1, k) u_(base)(1, k + 1) u_(base)(l, . . .) u_(base)(l, M) y_(2d)(l + 1) u_(base)(l + 1, 1) u_(base)(l + 1, . . .) u_(base)(l + 1, k) u_(base)(l + 1, k + 1) u_(base)(l + 1, . . . )u_(base)(l + 1, M) ⋮ u_(base)(⋮, 1) u_(base)(⋮, . . . )u_(base)(⋮, k) u_(base)(⋮, k + 1) u_(base)(⋮, . . . ) u_(base)(⋮, M)y_(2d)(N) u_(base)(N, 1) u_(base)(N, . . . ) u_(base)(N, k) u_(base)(N,k + 1) u_(base)(N, . . . ) u_(base)(N, M)the control values are calculated according to the following equation:

u _(base)(t)=l _(l,k) u _(base)(l,k)+l _(l+1,,k) u _(base)(l+1,k)+l_(l+1,,k+1) u _(base)(l+1+1,k)+l _(l,k+1) u _(base)(l,k+1)

wherein the weighting factors are formed as follows:

$\left. \begin{matrix}{{{0 < l_{l,k}} = {\frac{A\left( {l,k} \right)}{\sum A} \leq 1}},} & {{{0 \leq l_{l,{k + 1}}} = {\frac{A\left( {l,{k + 1}} \right)}{\sum A} < 1}},} \\{{{0 \leq l_{{l + 1},k}} = {\frac{A\left( {{l + 1},k} \right)}{\sum A} < 1}},} & {{0 \leq l_{{l + 1},{k + 1}}} = {\frac{A\left( {{l + 1},{k + 1}} \right)}{\sum A} < 1}}\end{matrix} \right\},$

and the regions are calculated as follows:

A(l,k)=[y _(1d)(k+1)−y _(1d) ][y _(2d)(l+1)−y _(2d)],

A(l+1,k)=[y _(1d)(k+1)−y _(1d) ][y _(2d) −y _(2d)],

A(l+1,k+1)=[y _(1d) −y _(1d)(k)][y _(2d) −y _(2d)(l)],

A(l,k+1)=[y _(1d) −y _(1d)(k)][y _(2d)(l+1)−y _(2d)],

Further information regarding the type of pilot control may be found inthe scientific article by O. Nelles and A. Fink; Tool for theoptimization of raster characteristic fields, 42, (2000), zurOptimierung von Rasterkennfeldern, 42 (2000), issue 5, atp, thedisclosure thereof being included here completely by reference inparticular in view of the calculation of the pilot control values.

For the purpose of simplicity, the execution of the adaptation processis further shown on the basis of a one-dimensional look-up table.Multi-dimensional characteristic fields or LUTs are matched adaptivelyin an analogous manner.

With an optimal layout and adjustment of the look-up table, thecontrolled portion u_(adder) of the control module (8) should ideally benear or equal to 0. The value of u_(adder)(t) is thus in the engagedcondition, that is, in the stationary or virtually stationary condition,a characteristic for the exactness of the pilot control characteristicdata, in particular for the heights or values of the current operatingor support point of adjacent nodes.

An arbitrary desired value y_(d)(∞) requires a control value, which isformed as u_(adder)(∞)+u_(base)(∞) according to FIG. 1. The infinitysign is thereby respectively for the engaged stationary and/or virtuallystationary condition.

The necessary control value can also be written asū_(addee)(∞)+u_(base)(∞)+Δu_(base)(∞). The correction value Δu_(base)(∞)for the pilot control value u_(base)(∞) is necessary, if the value ofthe controlled portion u_(adder)(∞) is too large. A suitable, newcontrolled portion ū_(addee)(∞) of the control module 8 shouldcorrespondingly be achieved by the correction value Δu_(base)(∞). Due tothe identityū_(adder)(∞)+u_(base)(∞)+Δu_(base)(∞)=u_(adder)(∞)+u_(base)(∞) the newcontrolled portion should be able to be written as follows:

ū _(adder)(∞)=u _(adder)(∞)−Δu _(base)(∞)=u _(adder)(∞)−[l _(k) Δu_(base)(k)+l _(k+1) Δu _(base)(k+1)].

The new controlled portion is preferably limited within a narrow band.This condition can be fulfilled by the optimal solution of the followingequation:

l _(k) Δu _(base)(k)+l _(k+1) Δu _(base)(k+1)=u _(adder)(∞)

As generally known, every equation of the form Ax=b has a solution inthe form of x*=A⁺b with the Moore-Penrose pseudo inverseA⁺=A^(T)(AA^(T))⁻¹, the necessary solution of the above equation isgiven as follows:

Δu* _(base) =L ⁺ u _(adder)(∞) wherein Δu* _(base) =[Δu* _(base)(k),Δu*_(base)(k+1)]^(T) and the pseudo

inverse is

$L^{+} = {{{\frac{1}{l_{k}^{2} + l_{k + 1}^{2}}\left\lbrack {l_{k},l_{k + 1}} \right\rbrack}^{T}\; L} = {\left\lbrack {l_{k},l_{k + 1}} \right\rbrack.}}$

So as to achieve a suitable distribution of the cooperation of differentcontrolled portions u_(adder) u_(adder)(∞) with the same delta pilotcontrol value Δu*_(base) with different control values y_(d)(∞), alimited updating rate is suggested as follows:

Δu* _(base) =ηL ⁺ u _(adder)(∞), wherein η=0,01 . . . 0,5=0.01 . . .0.5.

In the case of the two-dimensional look up tables, the pseudo inversecan be calculated as follows:

$L^{+} = {\frac{1}{l_{l,k}^{2} + l_{{l + 1},k}^{2} + l_{{l + 1},{k + 1}}^{2} + l_{l,{k + 1}}^{2}}\left\lbrack {l_{l,k},l_{{l + 1},k},l_{{l + 1},{k + 1}},l_{l,{k + 1}}} \right\rbrack}$

Δu*_(base)=[Δu*_(base)(l,k),Δu*_(base)(l+1,k),Δu*_(base)(l+1,k+1),Δu*_(base)(l,k+1)]^(T)The adaptive algorithm for updating the pilot control characteristicdata can be written altogether as follows:

Step 1: check if the controlled part u_(adder) exceeds a boundary value.

This is for example checked by the condition

$\left\{ {{{\frac{}{t}\left\lbrack {{y_{m}(t)}\frac{1}{{T_{y}s} + 1}} \right\rbrack}} < y_{0}^{limit}} \right\}$

If the boundary value is exceeded, the adaptation process is initiated,otherwise an adaptation process does not take place;

the immediately adjacent support points of the characteristic field arecalculated to the desired value y_(d)(t) in step 2;the pseudo inverse L⁺ of the evaluation function L is calculatedcorresponding to the above equations in step 3;the characteristic field is updated corresponding to the followingequation in step 4:

u _(base) ^(new) =u _(base) ^(old) +Δu* _(base) +ηL ⁺ u _(adder)(∞)

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

1.-11. (canceled)
 12. Open-loop and closed-loop control apparatus for controlling at least one controlled variable of a system, said control apparatus comprising: a pilot control module with an associated storage module for storing pilot control characteristic data, said pilot control module being configured to carry out pilot control wherein a pilot control value is determined on the basis of a desired value of the controlled variable from the pilot control characteristic data; and a closed-loop control module, which is configured to perform closed-loop control of the controlled variable, with a controlled portion being determined on the basis of an actual value of the controlled variable; wherein, the pilot control value and the controlled portion each contribute respectively to a control value or a manipulated variable; and said control apparatus further comprises an adaptation module, for matching the pilot control characteristic data in the storage module adaptively during the run time of the open-loop control apparatus.
 13. The open-loop and closed-loop control apparatus according claim 12, wherein the pilot control characteristic data are formed as one of a characteristic, a characteristic field, and a raster characteristic or raster characteristic field.
 14. The open-loop and closed-loop control apparatus according to claim 12, wherein the adaptation module adapts the pilot control characteristic data on the basis of the controlled portion.
 15. The open-loop and closed-loop control apparatus according to claim 14, wherein controlled portions used for the adaptation are taken from one of the closed-loop control module and the system with a stationary and/or a virtually stationary condition.
 16. The open-loop and closed-loop control apparatus according to claim 12, wherein the pilot control characteristic data are adapted using at least one of a surface interpolation method and a linear interpolation method.
 17. The open-loop and closed-loop control apparatus according to claim 12, wherein an adaptation degree of the pilot control characteristic data is less than 100% per adaptation process.
 18. The open-loop and closed-loop control apparatus according to claim 12, wherein an adaptation degree of the pilot control characteristic data is in the region of 1% to 50%.
 19. The open-loop and closed-loop control apparatus according to claim 12, wherein the adaptation of the pilot control characteristic data takes place only with currently unused pilot control characteristic data.
 20. The open-loop and closed-loop control apparatus according to claim 12, wherein the manipulated variable acts on at least one of an air compressor, an exhaust gas throttle flap, a humidifier bypass throttle flap, a pressure control valve and a recirculation pump of a fuel cell system.
 21. The control apparatus according to claim 12, wherein said system is a fuel cell system.
 22. A method for the control of at least one controlled variable of a system using the open-loop and closed-loop control apparatus according to claim 12, wherein a pilot control value is determined based on a desired value of the controlled variable from stored pilot control characteristic data; a controlled portion is determined based on an actual value of the controlled variable; a control value is formed based on the pilot control value and the controlled portion; and the pilot control characteristic data are matched in an adaptive manner during a run time of the system. 